Engineered Marine Products 300-15189 MerCruiser High-Output Replacement Alternator 105A Motorola IR/EF Universal Mount

The Engineered Marine Products 300-15189 is a high-output 105-amp replacement alternator designed as a service replacement for MerCruiser inboard and sterndrive engines originally equipped with Motorola internal regulator/external fan (IR/EF) alternators. This unit is engineered specifically for marine use, delivering reliable electrical output to keep onboard systems and battery banks charged under demanding conditions.

Key Specifications:

• Output: High output 105 amp (replaces original 90A Motorola unit)
• Voltage: 12 Volt
• Regulator Type: Internal Regulator / External Fan (IR/EF)
• Mount Type: Universal mounting configuration
• Application: MerCruiser 1965–1977 service replacement

Cross-Reference Part Numbers:

• Mercury/MerCruiser OEM: 822982
• Sierra: 18-6955
• ARCO: 60121
• Volvo: 3860665

This alternator is built to replace worn or failed Motorola-type units used across a broad range of MerCruiser sterndrive and inboard engine applications from the mid-1960s through the late 1970s. The universal mounting design simplifies installation, and the upgraded 105-amp output provides improved charging capacity over the original 90-amp alternator it replaces—making it well-suited for boats with added electronics or dual-battery setups.